/*
 * Copyright (c) 2007-2012, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 1999-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: DTMNamedNodeMap.java,v 1.2.4.1 2005/09/15 08:15:03 suresh_emailid Exp $
 */
package com.sun.org.apache.xml.internal.dtm.ref;

import com.sun.org.apache.xml.internal.dtm.DTM;

import org.w3c.dom.DOMException;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;

/**
 * DTMNamedNodeMap is a quickie (as opposed to quick) implementation of the DOM's
 * NamedNodeMap interface, intended to support DTMProxy's getAttributes()
 * call.
 * <p>
 * ***** Note: this does _not_ current attempt to cache any of the data;
 * if you ask for attribute 27 and then 28, you'll have to rescan the first
 * 27. It should probably at least keep track of the last one retrieved,
 * and possibly buffer the whole array.
 * <p>
 * ***** Also note that there's no fastpath for the by-name query; we search
 * linearly until we find it or fail to find it. Again, that could be
 * optimized at some cost in object creation/storage.
 * @xsl.usage internal
 */
public class DTMNamedNodeMap implements NamedNodeMap {

    /** The DTM for this node. */
    DTM dtm;

    /** The DTM element handle. */
    int element;

    /** The number of nodes in this map. */
    short m_count = -1;

    /**
     * Create a getAttributes NamedNodeMap for a given DTM element node
     *
     * @param dtm The DTM Reference, must be non-null.
     * @param element The DTM element handle.
     */
    public DTMNamedNodeMap(DTM dtm, int element) {
        this.dtm = dtm;
        this.element = element;
    }

    /**
     * Return the number of Attributes on this Element
     *
     * @return The number of nodes in this map.
     */
    public int getLength() {

        if (m_count == -1) {
            short count = 0;

            for (int n = dtm.getFirstAttribute(element); n != -1; n = dtm.getNextAttribute(n)) {
                ++count;
            }

            m_count = count;
        }

        return (int) m_count;
    }

    /**
     * Retrieves a node specified by name.
     * @param name The <code>nodeName</code> of a node to retrieve.
     * @return A <code>Node</code> (of any type) with the specified
     *   <code>nodeName</code>, or <code>null</code> if it does not identify
     *   any node in this map.
     */
    public Node getNamedItem(String name) {

        for (int n = dtm.getFirstAttribute(element); n != DTM.NULL; n = dtm.getNextAttribute(n)) {
            if (dtm.getNodeName(n).equals(name))
                return dtm.getNode(n);
        }

        return null;
    }

    /**
     * Returns the <code>index</code>th item in the map. If <code>index</code>
     * is greater than or equal to the number of nodes in this map, this
     * returns <code>null</code>.
     * @param i The index of the requested item.
     * @return The node at the <code>index</code>th position in the map, or
     *   <code>null</code> if that is not a valid index.
     */
    public Node item(int i) {

        int count = 0;

        for (int n = dtm.getFirstAttribute(element); n != -1; n = dtm.getNextAttribute(n)) {
            if (count == i)
                return dtm.getNode(n);
            else
                ++count;
        }

        return null;
    }

    /**
     * Adds a node using its <code>nodeName</code> attribute. If a node with
     * that name is already present in this map, it is replaced by the new
     * one.
     * <br>As the <code>nodeName</code> attribute is used to derive the name
     * which the node must be stored under, multiple nodes of certain types
     * (those that have a "special" string value) cannot be stored as the
     * names would clash. This is seen as preferable to allowing nodes to be
     * aliased.
     * @param newNode node to store in this map. The node will later be
     *   accessible using the value of its <code>nodeName</code> attribute.
     *
     * @return If the new <code>Node</code> replaces an existing node the
     *   replaced <code>Node</code> is returned, otherwise <code>null</code>
     *   is returned.
     * @exception DOMException
     *   WRONG_DOCUMENT_ERR: Raised if <code>arg</code> was created from a
     *   different document than the one that created this map.
     *   <br>NO_MODIFICATION_ALLOWED_ERR: Raised if this map is readonly.
     *   <br>INUSE_ATTRIBUTE_ERR: Raised if <code>arg</code> is an
     *   <code>Attr</code> that is already an attribute of another
     *   <code>Element</code> object. The DOM user must explicitly clone
     *   <code>Attr</code> nodes to re-use them in other elements.
     */
    public Node setNamedItem(Node newNode) {
        throw new DTMException(DTMException.NO_MODIFICATION_ALLOWED_ERR);
    }

    /**
     * Removes a node specified by name. When this map contains the attributes
     * attached to an element, if the removed attribute is known to have a
     * default value, an attribute immediately appears containing the
     * default value as well as the corresponding namespace URI, local name,
     * and prefix when applicable.
     * @param name The <code>nodeName</code> of the node to remove.
     *
     * @return The node removed from this map if a node with such a name
     *   exists.
     * @exception DOMException
     *   NOT_FOUND_ERR: Raised if there is no node named <code>name</code> in
     *   this map.
     *   <br>NO_MODIFICATION_ALLOWED_ERR: Raised if this map is readonly.
     */
    public Node removeNamedItem(String name) {
        throw new DTMException(DTMException.NO_MODIFICATION_ALLOWED_ERR);
    }

    /**
     * Retrieves a node specified by local name and namespace URI. HTML-only
     * DOM implementations do not need to implement this method.
     * @param namespaceURI The namespace URI of the node to retrieve.
     * @param localName The local name of the node to retrieve.
     *
     * @return A <code>Node</code> (of any type) with the specified local
     *   name and namespace URI, or <code>null</code> if they do not
     *   identify any node in this map.
     * @since DOM Level 2
     */
    public Node getNamedItemNS(String namespaceURI, String localName) {
        Node retNode = null;
        for (int n = dtm.getFirstAttribute(element); n != DTM.NULL; n = dtm.getNextAttribute(n)) {
            if (localName.equals(dtm.getLocalName(n))) {
                String nsURI = dtm.getNamespaceURI(n);
                if ((namespaceURI == null && nsURI == null) || (namespaceURI != null && namespaceURI.equals(nsURI))) {
                    retNode = dtm.getNode(n);
                    break;
                }
            }
        }
        return retNode;
    }

    /**
     * Adds a node using its <code>namespaceURI</code> and
     * <code>localName</code>. If a node with that namespace URI and that
     * local name is already present in this map, it is replaced by the new
     * one.
     * <br>HTML-only DOM implementations do not need to implement this method.
     * @param arg A node to store in this map. The node will later be
     *   accessible using the value of its <code>namespaceURI</code> and
     *   <code>localName</code> attributes.
     *
     * @return If the new <code>Node</code> replaces an existing node the
     *   replaced <code>Node</code> is returned, otherwise <code>null</code>
     *   is returned.
     * @exception DOMException
     *   WRONG_DOCUMENT_ERR: Raised if <code>arg</code> was created from a
     *   different document than the one that created this map.
     *   <br>NO_MODIFICATION_ALLOWED_ERR: Raised if this map is readonly.
     *   <br>INUSE_ATTRIBUTE_ERR: Raised if <code>arg</code> is an
     *   <code>Attr</code> that is already an attribute of another
     *   <code>Element</code> object. The DOM user must explicitly clone
     *   <code>Attr</code> nodes to re-use them in other elements.
     * @since DOM Level 2
     */
    public Node setNamedItemNS(Node arg) throws DOMException {
        throw new DTMException(DTMException.NO_MODIFICATION_ALLOWED_ERR);
    }

    /**
     * Removes a node specified by local name and namespace URI. A removed
     * attribute may be known to have a default value when this map contains
     * the attributes attached to an element, as returned by the attributes
     * attribute of the <code>Node</code> interface. If so, an attribute
     * immediately appears containing the default value as well as the
     * corresponding namespace URI, local name, and prefix when applicable.
     * <br>HTML-only DOM implementations do not need to implement this method.
     *
     * @param namespaceURI The namespace URI of the node to remove.
     * @param localName The local name of the node to remove.
     *
     * @return The node removed from this map if a node with such a local
     *   name and namespace URI exists.
     * @exception DOMException
     *   NOT_FOUND_ERR: Raised if there is no node with the specified
     *   <code>namespaceURI</code> and <code>localName</code> in this map.
     *   <br>NO_MODIFICATION_ALLOWED_ERR: Raised if this map is readonly.
     * @since DOM Level 2
     */
    public Node removeNamedItemNS(String namespaceURI, String localName) throws DOMException {
        throw new DTMException(DTMException.NO_MODIFICATION_ALLOWED_ERR);
    }

    /**
     * Simple implementation of DOMException.
     * @xsl.usage internal
     */
    public class DTMException extends org.w3c.dom.DOMException {
        static final long serialVersionUID = -8290238117162437678L;

        /**
         * Constructs a DOM/DTM exception.
         *
         * @param code
         * @param message
         */
        public DTMException(short code, String message) {
            super(code, message);
        }

        /**
         * Constructor DTMException
         *
         *
         * @param code
         */
        public DTMException(short code) {
            super(code, "");
        }
    }
}
